Time to gut a sick cat!

[Lezard]

Alright, my car was running rich for about half a year. . . And I crushed the upper section of my exhaust by letting it roll down a hill over a curb(I wouldn't trust an Alfa parking brake). Anyways, fixed the exhaust, fixed the AFM, and the car runs nice now, but the sound is awful, and the power up high is. . . Lacking.

So I'm suspecting my cat has melted into oblivion, and needs to be gutted. I would get a straight pipe, but who has that kind of cash?

Has anyone here ever gutted a cat? How do you do it? Is it something I can do in my driveway with no jacks or lifts, or help from anyone? Special tools? Oh, and how exactly do you gut the cat once it's freed from the car? Thanks guys!

[slyalfa]

if the OEM I think it is full of pellets and wold be hard to do. if after market they gut them selves if run rich, hit a rock, one backfire etc.

No SMOG test there??
The aftermarket ones are cheap and the power gain is a lot.
stop by a muffler shop if no SMOG test where you are the muffler shop should be able to fix you up cheap. if you do get a new cat look at around $100 installed. any more and you are getting ripped off.

[Rookie ROX]

Look it's ultimately not hard or complicated process by any means - It's really just thrusting a crow bar or large piece of pipe or similar into the cat and breaking everything up. Then you just give it a shake and repeat the process until you've got most of it.

That said, an exhaust shop should be able to fit a straight pipe in replacement pretty damn cheaply. As sly has alluded to, aftermarket cats aren't that expensive either. Magnaflow do some nice work. So it does come down to whether you need to do any SMOG testing, just need the appearance of a cat or can get away with not having to bother at all.

ROCK ON
R~R

[Lezard]

Oh interesting news. So an exhaust shop like Midas could just fit a straight pipe in for under $100 you guys think? Too cool.

What kind of power gains can I expect for a straight pipe and no cat? I'm starting to get more excited now. . .

Fortunately Minnesota has no emissions testing of any kind. I think it's because they want to keep old Alfas on the road. . .

[JoeCab]

Quote:

Originally Posted by Lezard Fortunately Minnesota has no emissions testing of any kind. I think it's because they want to keep old Alfas on the road. . .

[Travis_k]

Although they rarely check, it is against federal law to remove/gut a cat, and if you get pulled over by a cop in a really bad mood, they can fine you and tow your car. IMO, just get a cheap replacement cat, its a way better idea.

[Duk]

Here in Oz, removing a cat could cost $10,000 .

Cats with the guts knocked out of them tend to flow badly aswell. A decent increase in volume/cross sectional area causes a build up of pressure (resistance to flow).
Some time this isn't as bad as a poor flowing cat, but if the standard cat (in decent condition) isn't providing enough flow restriction to reduce performance, it's a fare bet that a gutted cat will.

[Lezard]

Well, my Spider has no cat. I'm not afraid. I want to do this CHEAPLY, so a replacement cat is far from an option. It's either gut, or straight pipe. I suppose I'd prefer straight pipe. I'll pay some shop cash, and keep it off the books. I should be fine.

I can throw some collector plates on it, and classify it as a hobby race car. How do you think I buy non-ethanol fuel?

So how big of a power increase can I expect? 20hp? I'm excited now. Thanks for the advice guys.

[Travis_k]

If you still have the stock exhaust, there is no way to really put a straight pipe in without replacing the whole thing, becasue one pipe goes into the cat, then its 2 small pipes for most of the way under the car (becasue the designers forgot to leave room for an exhaust system, and thats the only way to get enough clearance). The best (and cheapest if you dont really have alot of tools) way to fix it is to buy a $90 magnaflow cat from here Family Car - Auto Parts and Accessories Catalog - Alfa Romeo Milano Catalytic Converter - Alfa Romeo Milano and take it and have it welded on. To remove the cat and gut it you will at least need a large jack and some decent sized jack stands. I just walked outside and looked at mine, and I dont think removing the cat without it on a lift would be fun at all. You will be more likely to find a shop that will charge you $100 to weld in a $90 cat then one that will risk a $10k fine from the EPA for removing one, and if you dont have the tools, you would spend at least $200 getting the stuff you would need to remove the cat and gut it.

[slyalfa]

also it is my guess the the system is tuned to have a expander there. so going with a pipe would lose power. So if you do lose the cat put a muffler there.

[Duk]

Quote:

Originally Posted by slyalfa also it is my guess the the system is tuned to have a expander there. so going with a pipe would lose power. So if you do lose the cat put a muffler there.

[Lezard]

Quote:

Originally Posted by Duk Me thinks you are expecting waaaaay to much from the Alfa Romeo design team! They failed in many areas of building these cars (tho I still want mine in 1 piece again ), and you think they went to some great trouble to have some really well tuned exhaust after such an ordinary pair of manifolds (on the V6s. tho probably heeeaps better than most Aussie/American engines of that era) that relied on some specific cat converter volume and/or diameter? Please don't mention back pressure and torque in the same sentence. That is a factual misinterpretation of what happens. If Mr (or Mrs) thread starter wants some sort of dodgy, illegal cat replacement, I'd sujest that they put a piece of pipe that is the same diameter as the rest of the exhaust inside the cat body. Tho a new, replacement cat is the obvious true sollution.

[Travis_k]

Do you still have the original exhaust system on your car? if so, it would be impossible to replace only the car using a single piece of pipe. That was the main reason I suggested a $90 replacment cat. If the whole thing has been changed, and you dont mind doing most of the work (including some welding) the other suggestions wold be fine.

[genius]

Lezard... I'd like to say go with the straight-through pipe but it sounds like you'll be pulling the tiger's tail

Makes me thankful that I live in a Third World Country (or is it the Political South now?)...

...No Cat No EPA Great sounding exhaust

(Not sure if you've seen my other post... Do you want an owners manual? I've got a spare one around the house somewhere!!)

Cheers

Mike

[Lezard]

Ahh, so it seems a straight pipe can't be done very cheaply at a shop huh? I was hoping to seal the deal for around $100. $200 would be the absolute limit.

And genius. . . I'd LOVE an owners manual!